<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="./js/vue.js"></script>
    <style>
        .hotpink{
            color: hotpink;
        }
        .deeppink{
            color: green;
        }
    </style>
</head>
<body>
      <div id="app">
          <p :class="pClass">
              城市套路深 我要回农村 农村路更滑 人心更复杂
          </p>
          <button @click="handleC">click</button>
      </div>
</body>
<script>
    Vue.config.productionTip=false;
    var vm = new Vue({
        el:"#app",
        data:{
            pClass:"hotpink"
        },
        methods:{
            handleC(){
                this.pClass="deeppink"
            }
        }
    })
</script>
</html>